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1984-1990 Corvette C4 ACI Motor Sports Wide Body Kit with Rear Tunnel

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Brand Logo American Custom Industries - ACI
Item ID: 611-172
Availability: Ships Directly From Supplier
   Pending Manufacturer Availability
Fits Years:
  • 1984-1990
$3,099.99
Shipping: Truck Freight Required
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  • Description
  • What Is Truck Freight

1984-1990 C4 ACI Motor Sports Wide Body Kit with Rear Tunnel

Transform your C4 into a track-inspired showstopper with the ACI Motor Sports Wide Body Kit—designed to enhance both the performance and appearance of your 1984–1990 Corvette. This bolt-on aerodynamic package reduces wind resistance, improves airflow, and increases downforce without compromising drag. It’s engineered for performance enthusiasts and show car builders alike.

The kit includes lower side skirts, an aggressive front spoiler, the ACI Rear Tunnel which neatly conceals the spare tire while retaining access to the lower pan, and the ACI Rear Wing, which delivers improved rear stability with virtually no added aerodynamic penalty.

Each fiberglass component arrives with a smooth gel coat finish, ready to be test-fitted, primed, and painted to match your Corvette’s personality. Proudly Made in the USA and shaped to command attention on both road and track.

Features
     • Fits 1984–1990 C4 Corvettes
     • Complete ACI Motorsport Wide Body Kit
     • Includes ACI Rear Wing for increased downforce
     • Includes ACI Rear Tunnel—conceals spare tire area
     • Aggressive front spoiler improves airflow
     • Lower side skirts reduce drag
     • Retains access to spare tire lower pan
     • Superior gel coat finish—ready to prime and paint
     • Made in the USA

Dimensions and Weight
     • Application: 1984–1990 C4
     • Material: Hand-Laid Fiberglass
     • Finish: White Gel Coat
     • Shipping: Truck Freight Recommended

Gel Coat Finish & Handling of Imperfections
The main thing we stress is that all fiberglass parts must be fitted to the car before any paint work is started. As you and we both know—no two Corvettes are the same. Expect minor prep work for proper alignment. We recommend test-fitting all panels, making adjustments, and then proceeding with primer and paint for best final results.

Hand-Laid vs. Press Molded Fiberglass
Original GM panels were press molded—a fast production method using high pressure to produce thin, uniform parts with smooth surfaces. However, they’re prone to stress cracking and distortion over time. Our hand-laid fiberglass is manually layered with resin-saturated mat, resulting in thicker, stronger panels that better resist aging, are easier to modify, and deliver superior long-term durability. While slightly heavier, they provide excellent fitment for restorations that demand strength and precision.

Because Fit and Finish Matter
This wide body kit isn’t built to duplicate GM’s factory process—it’s engineered for today’s real-world Corvettes. Whether you're carving corners at the track or building a head-turning street machine, ACI’s package delivers aggressive styling, superior fitment, and aerodynamic advantage in one bold upgrade.

Learn more from the following Mid America Motorworks Knowledge Library article:

Corvette Body Components from Fiberglass to Resin Transfer Molding



Also known under these part numbers: (For reference only)

  • 686420284963
  • AGK015

Frequently Asked Questions Regarding Truck Freight

 

Question:  Why do my parts need to be shipped by truck?

Answer:  When Items that are too large to go by our normal carriers, they are shipped Truck Freight.

Question:  How is my freight price obtained?

Answer:  Freight pricing is based on multiple factors such as the shipment's freight class, density, route, and even how the items are packaged.  We contact a freight carrier and obtain shipping costs. We then add this to you order.

Question:  What do I or the freight company need to know about delivery?

Answer: You should know that your address (receiving location) needs to be adequate to accommodate a semi-truck.

 

Money Saving TIP: Typically we encourage you to provide a commercial address for delivery. Commercial locations/facilities can accommodate a large truck delivery and rates are often much less expensive.

 

Question:  What happens when I place an order that requires truck freight?

Answer: After your order is placed and we contact the freight company for rates, we call you and advise the specific details of the shipment.

Questions: What are the meanings of classifications?

Answer: Each item is classified within specific carrier guidelines. These guidelines are the class of an item and the related costs, density and inherent risks of transporting such an item. All items shipped by MAM have been evaluated as to the most economical fright classification prior to shipping.

Question: How will this item be unloaded?

Answer: The carrier delivers to your destination and it is available to you at the “end of their trailer”.  It is your responsibility to be able to get it off the truck,

Question: What about heavy items like motors, transmissions and complete front ends?

Answer: If you are going to need a truck with a lift gate, we need to know that in advance of getting a quote for freight costs. If your items are to be delivered to a location with a freight dock, we also need to know that information.

 

Additional Ordering and Truck Freight Information Needed:

Your order will not be process until we receive YOUR approval and additional information for the freight delivery.  If we do not get your approval after 7 days, your order will be cancelled.

Make sure to provide a current telephone number. Shipping carrier will usually contact you directly to arrange a delivery date and time.

Someone should be present for delivery to sign for the shipment.

Check to make sure the shipment arrives in good condition and note any damage on the shipping receipt before the driver leaves.

 

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